Room-to-Room Heat Pump

ABSTRACT

A system, method, and device for transferring thermal energy between areas of a structure so as to maintain occupant comfort while minimizing the difference between indoor and outdoor temperatures, thereby minimizing thermal losses from the structure. The device operates effectively in the heating season and cooling season, when outdoor temperatures are cold and hot, respectively.

RELATED APPLICATIONS

This claims the benefit of U.S. Provisional Application Ser. No.62/030,320, filed Jul. 29, 2014, entitled ROOM-TO-ROOM HEAT PUMP, theentire disclosure of which is herein incorporated by reference and thebenefit of U.S. Provisional Application Ser. No. 62/131,436, filed Mar.11, 2015, entitled ROOM-TO-ROOM HEAT PUMP, the entire disclosure ofwhich is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to the heating and cooling of individualrooms of a house by means of available heat from other rooms of thehouse, and manipulating the temperatures of these rooms in order tominimize the heat lost from the house, utilizing a forced hot air typeheating system.

BACKGROUND OF THE INVENTION

The rate of heat loss out of a home is proportional to the differencebetween the indoor temperature and the outdoor temperature. When thisgradient is especially high, such as during winter nights, a typicalhome can lose over 44,000 Btu per hour (Build it Solar. “Home Heat LossCalculator”.<http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm>.Date of Access: 7/25/14.). At current oil prices, this represents $1.27per hour in wasted fuel.

To improve this situation, many homeowners currently employ a methodcalled night setback. In night setback mode, the homeowner lowers thethermostat several degrees during the night. As the difference betweenthe indoor and outdoor temperature decreases due to heat loss, the rateof heat loss out of the house decreases as well. Since most of the homeisn't occupied during this time, the temperature may drop belowcomfortable levels. Energy usage studies have found savings of around 6%for typical homes using night setback (Manning, M. M., M. C. Swinton, F.Szadkowski, J. Gusdorf, and K. Ruest. “The Effects of ThermostatSet-back in winter and Set-up during summer on Seasonal EnergyConsumption, Surface Temperatures and Recovery Times at the CCHT TwinHouse Facility.” ASHRAE Transactions 113: 1-12). Furthermore, heatingbills are reduced by approximately 1% per degree of nightly indoortemperature reduction.

Although night setback saves on heating costs, it has some limitations.First, the number of degrees setback is limited by the rate of heat lossfrom the home. That is, the degrees of setback cannot exceed the degreesnormally lost throughout the night, as setback is a passive method. Thetypical recommended night setback is only 8° F. This means that theenergy savings are limited to a fairly modest percentage of the overallbill on the order of 5%-8%.

The second major limitation of night setback is that the home may becometoo cold for comfort in the morning. To address this, the furnace orboiler may be turned on some time before the homeowner wakes up using aprogrammable thermostat. However, turning the furnace or boiler onearlier markedly reduces energy savings. In fact, it is for this reasonthat programmable thermostats, which purport to reduce heating costs byfacilitating setback, lost their Energy Star rating (Jim Gunshinan.“Energy Star Changes Approach to Programmable Thermostats”. Home EnergyMagazine. March/April 2007 issue.<http://www.waptac.org/data/files/website docs/technical tools/energystar/energy star changes approach to programmable thermostate.pdf>.).

A related technology to the Room-to-Room Heat Pump invention is theair-to-air heat pump, which has been adopted by some homeowners as ahome heating system. Air sourced heat pumps extract heat from theoutdoor air and move it inside. They are quite efficient, with a typicalcoefficient of performance (“COP” which is a ratio of heating or coolingprovided to electrical energy consumed) of 3, but suffer fromperformance decrease in cold weather. When the outdoor temperature fallsbelow about 40° F., the coils on the heat pump's compressor begin tofrost over. As this happens, the heat pump must use energy to defrostthe coils, which decreases efficiency. In addition, there is lessavailable energy in the air at colder temperatures, which causes heatpumps to work harder to warm the homes. Below a certain temperature,heat pumps must call on a backup heating system, typically electricresistive heating. Electric resistive heating has a COP of 1, so relyingon the backup heating system also decreases efficiency.

DESCRIPTION OF THE INVENTION

The Room-to-Room Heat Pump reduces heating costs by reducing heat lossto the outside at night by decreasing the difference between theunoccupied indoor rooms' temperature and the outdoor temperature. Ratherthan passively allowing the temperature of the home to drop as in thesetback case, the heat pump actively lowers the temperature in somerooms or parts of the house, typically those unoccupied during certainhours or days, by pumping heat from those portions of the house that areunoccupied to portions of the house that are occupied. This subsequentlydecreases the rate at which heat escapes from the unoccupied portions ofthe home. The aim of the Room-to-Room Heat Pump invention is to bringthe temperature of the unoccupied areas of the home as close to theoutdoor temperature as is safely possible, thereby limiting the rate ofheat loss from the home.

This process is achieved by means of an indoor-air sourced heat pumpcompactly installed within the house. The heat pump transfers thermalenergy between rooms or portions in the house, rather than with theoutdoors, and may be reversed such that heat can flow in eitherdirection between such portions. The ability of the heat pump to reversedirection enables it to operate in both the summer and winter and allowsthe movement to and from certain rooms of the house.

In the preferred embodiment of the invention, the heat pump removes heatfrom an unoccupied room and transfers it to an occupied room at apre-determined time. This decreases the temperature gradient for theportion of the house giving up heat while maintaining the occupied roomsat a comfortable temperature. The activation time may be set manually bythe homeowner. Alternatively, a programmable smart thermostat mayautomatically learn the homeowner's behavior and adjust the roomtemperatures accordingly. The heat pump in this invention has an assumedCoefficient of Performance (COP) of 3, which is standard performance foran air-to-air heat pump. This means that for every unit of energy putinto the device, it moves 3 units of energy in the form of heat. Thefact that the heat pump is located inside the heating envelope of thehouse allows the waste heat produced by the machine to itself to be usedas a heat source for the house itself thus reducing the cost of movingheat from room to room during the heating season. Given this energyrecapture, the largest cost to run the system is therefore thedifference in cost per BTU between the electricity used to run the heatpump and the cost of a BTU provided by the house's normal heat source,which could be oil, propane, etc. Problems with icing on compressorcoils are avoided by maintaining the home temperature above the icingtemperature.

This level of efficiency enables the invention to rapidly move heat fromone area of the home to another and to do so at a low cost. The cost ofoperating the heat pump must be lower than the savings in order tojustify the installation of the invention. As is proved in a latersection, the savings are greater than the cost of operation.

BRIEF DESCRIPTION OF THE FIGURES

The invention description below refers to the accompanying drawings, ofwhich:

FIG. 1 is an overview block diagram for the invention in heating seasonmode during night operation;

FIG. 2 is a diagram of the invention in a house in heating season modeduring night operation;

FIG. 3 is an overview block diagram for the invention in heating seasonmode during morning operation;

FIG. 4 is a diagram of the invention in a house in heating season modeduring morning operation;

FIG. 5 is an overview block diagram for an embodiment of the inventionwith thermal storage in heating season mode during night operation;

FIG. 6 is a diagram of an embodiment of the invention with thermalstorage in a house in heating season mode during morning operation;

FIG. 7 is an overview block diagram for the invention in cooling seasonmode during night operation;

FIG. 8 is a diagram of the invention with heat rejection capability;

FIG. 9A is a diagram of the HVAC integration method of inventioninstallation;

FIG. 9B is a diagram of mobile small-footprint method of inventioninstallation;

FIG. 10 is a diagram showing the air curtain embodiment of theinvention.

FIG. 11 is a diagram of a house using a forced hot air system using aheat pump to transfer heat between rooms.

FIG. 12 is a diagram of a two story house with two furnaces using a heatpump to transfer heat between the rooms.

FIG. 13 is a diagram of a multi-evaporator, multi-condenser heatexchange system.

FIG. 14 is a diagram of a water tank heat sink system

FIG. 15 is a diagram of a concrete heat sink system

FIG. 16 is a diagram of a two story house with a multi-zone furnaceusing a heat pump system to move heat between rooms.

FIG. 17 is a thermostat logic diagram for the simplest iteration of theproduct.

FIG. 18 is a thermostat logic diagram for the iteration which includesthe heat sink component.

DETAILED DESCRIPTION OF FIGURES

FIG. 1 shows Room-to-Room Heat Pump nighttime operation in heatingseason mode. A room-to-room heat pump 2 is installed between two floorsof a two floor home 1. The Room-to-Room heat pump 2 operates between anoccupied area 3 and an unoccupied area 4. Due to cold weather, heatedair is required in the occupied area 3. The Room-to-Room heat pump 2draws air from the unoccupied area 4 into an intake vent 9. A damper 8is automatically positioned so that air from the top of the unoccupiedarea 4, which is warmer than air from the bottom of the area due to warmair's tendency to rise, is drawn into heat pump 2. A second damper 5 isautomatically positioned so that air exits the heat pump 2 at a lowervent 6. Cool air is exhausted back into the unoccupied area 4 from anexhaust vent 7.

FIG. 2 describes the home heating pump process flow for heating seasonmode during nighttime use. Exemplary sleep and wake times andtemperatures are used herein for purpose of clarity. If the time isafter 11:00 PM and before 6:00 AM (step 10), the living area thermostatfor the first floor, the unoccupied space, is lowered to 40° F. (step11). At the same time, the heat pump is activated (step 12). The heatpump monitors the temperature of the sleeping area until the sleepingarea temperature drops below 70° F. (step 13). (Note that throughoutthis document we use 70° F. as the desired temperature of a room and 40°F. for the coldest point that a room should be allowed to get. Inpractice, both of these numbers would be configurable by a user or aninstaller.) If the sleeping area temperature is not below 70° F., theheat pump continues to monitor the room temperature (step 15). If thesleeping area temperature is below 70° F. (step 14), the heat pumpremoves heat from the living area (step 16). It adds this heat to thesleeping area (step 17). The cold air is exhausted back into the livingarea. The device also monitors the temperature of the living area (step18). If the living area temperature drops below 40° F. (step 19), theheat pump shuts off (step 21). The heat pump then continues to monitorthe living area temperature (step 22 and 23) until the living areatemperature is above 40° F. (step 24). If the living area temperature isabove 40° F., the heat pump continues to remove heat from the livingarea (step 25) and transfers it to the occupied areas when thetemperature of such occupied areas falls below 70 degrees.

FIG. 3 shows the process for morning operation in heating season mode.The morning is a transition time, when both the sleeping and livingareas may be occupied, so both are kept at comfortable temperatures.When the time is after 6:00 AM and before 11:00 PM (step 26), theRoom-to-Room Heat Pump enters morning mode. A solenoid valve in the heatpump switches, causing the direction of heat pumping to reverse (step27). At the same time, the living area thermostat is raised to 70° F.(step 28). The Room-to-Room Heat Pump evaluates whether the living areatemperature is below 70° F. (step 29). If it is not (step 30), theprocess returns to step 29. If it is (step 31), the Room-to-Room HeatPump then evaluates whether the sleeping area temperature is above 40°F. (step 32). If it is (step 34), heat is removed from the sleeping area(step 35) and added to the living area (step 36). The device proceeds tostep 29 and continues to monitor the room temperatures and continuesthrough the previously described process until the morning period ends.

FIG. 4 describes Room-to-Room Heat Pump operation in morning heatingseason mode within a two floor home 37. Air from the sleeping area 38enters the top sleeping area vent 40. The vent carries the air to theheat pump 42, which extracts heat from air in the sleeping area 38. Theresulting cooled air is exhausted back into the sleeping area 39 at thelower sleeping area vent 44. The warmed air exits the Room-to-Room HeatPump at the exhaust vent 41. Dampers 43 are automatically positioned asshown to facilitate the described movement of air. The result of themorning heating season mode operation is that the sleeping areatemperature is decreased while the living area temperature is raised.

FIG. 5 describes Room-to-Room Heat Pump operation in heating season modein the nighttime for an alternate conception with thermal storagecapabilities. If the time is after 11:00 PM and before 6:00 AM (step45), the living area thermostat is lowered to 40° F. (step 46). At thesame time, the heat pump is activated (step 47). The heat pump removesheat from the living area (step 48) and adds it to the storage tank(step 49). The device evaluates whether the sleeping area temperature isbelow 70° F. (step 50). If not, it continues to monitor the temperature(step 51). If the temperature of the sleeping area is below 70° F. (step52), heat is removed from the storage tank (step 52B) and added to thesleeping area (step 53). The device then continues to monitor thesleeping area temperature (step 50).

The device also monitors the living area temperature (step 54). If theliving area temperature is not above 40° F. (step 55), the heat pumpceases to remove heat from the living area (step 57) until such time asthe living area temperature rises above 40° F. (steps 58 and 60). If theliving area is above 40° F. (step 60), the heat pump is reactivated(step 61) and the device proceeds to step 48.

FIG. 6 diagrams Room-to-Room Heat Pump operation in morning heatingseason mode with thermal storage capability in an exemplary two floorhome 62. Thermal energy is removed from the unoccupied area 63 andstored in the thermal storage tank 70. Thermal storage tank 70 is alarge vessel composed of and/or filled with a material with a highspecific heat capacity. In one embodiment, the thermal storage tank 70is made out of a metal such as aluminum and filled with water. Thethermal storage tank 70 is heavily insulated to prevent heat loss.

Air from the unoccupied area 63 is drawn into the heat pump 65 at upperintake 66. The heat pump 65 extracts hot air and exhausts cool air backinto the unoccupied area 63 via 69. The valves 67 are automaticallyturned so as to facilitate the movement of the air in the prescribedpath to take it to the thermal storage tank. The ducts 71 are wrappedaround the thermal storage tank 70 in the manner of a heat exchanger tofacilitate the exchange of heat from the ducts 71 to the thermal storagetank 70. Alternatively, the warm air can go through an air-to-water heatexchanger to transfer the heat to the tank. Following this exchange, theresultant cool air is exhausted at the end of duct 71 into the basement.

When warm air is required, the direction of action may be reversed so asto draw cool air from the basement over the heat exchanger on thethermal storage tank 70 and move it to either room as required.

This method is an advantageous addition to the Room-to-Room heat pumpinvention because it enables the device to drive down the thermalgradient in unoccupied rooms without subsequently increasing thegradient in occupied rooms. Alternatively, it enables efficient storageof thermal energy during times when the entire home is unlikely to beoccupied, such as while the occupants are at work or away on a trip.Although occupants might turn down their thermostats in order to achievethe same lowering of the thermal gradient, the time to achieve such areduction via the slow emission of heat from the house will be muchlonger than if such heat loss (and subsequent storage in a heat tank) isdone actively with a heat pump.

FIG. 7 shows the process flow for the Room-to-Room Heat Pump innighttime cooling season operation. During the warm season of the year,the method of operation of the Room-to-Room Heat Pump may be switched toprovide cold air to the sleeping area without altering the method ofoperation.

When the time is within the pre-set nighttime hours (step 73), theliving space thermostat is raised to the ambient outdoor temperature(step 74). Alternatively, the home air conditioning system may bedeactivated. In the event that the home has no air conditioning system,this step is omitted. At the same time, the heat pump is activated (step75). The device monitors the occupied area, that is, the sleeping area,temperature (step 76). If the sleeping area temperature is below thepreset maximum threshold, no action is performed (step 77) and thedevice continues to monitor the occupied area temperature (step 76). Ifthe occupied area temperature is above the preset maximum threshold(step 78), the heat pump removes heat from the occupied area (step 79).Next, it evaluates whether the unoccupied area temperature is above athreshold temperature (step 80). This threshold may be the ambientoutdoor temperature or a pre-set temperature of the user's choice. Ifthe unoccupied area is above or below the temperature setting (step 82),heat is rejected to the outdoors (step 83). The device always radiatesheat to the outdoors. Following step 83, the device continues monitoringthe occupied area temperature (step 76).

FIG. 8A diagrams a method of operation of the Room-to-Room Heat Pumpwith heat rejection capability, an advantageous feature for coolingseason mode.

The ambient outdoor temperature 91 is warmer than the user findscomfortable, so he would like the occupied area 86 to have a lowertemperature. The heat pump 88 maintains the occupied room temperature 89at a preset temperature. The Room-to-Room Heat Pump uses air fromunoccupied areas of the home 87. This air is likely to be cooler tobegin with, which increases the efficiency of the heat pump 88.

Air is drawn into the lower intake vent 96 and passed through the heatpump 88. Excess heat is rejected to the atmosphere at the heat sink 92,which may passively reject heat with heat fins or actively with a fan.The air is then exhausted back into the unoccupied area 87 at the lowerexhaust vent 95, while the occupied room 86 is cooled by air from uppervent 93. Automatic valves 94 are adjusted as shown to facilitate thismovement.

FIG. 9A diagrams the heating, ventilation, and air conditioning (HVAC)system integration method of installation of the Room-to-Room Heat Pump103. The Room-to-Room Heat Pump 103 is integrated into the home HVACsystem and ductwork, said system comprising a heat provider such as afurnace or boiler 104 and ductwork 99, 101, 102, 107. 101 and 102 aredirect access with outdoor air, which would be useful in certainsituations and would remain unused in other situations. In thediagrammed installation, the home has multiple heating and cooling zones98, 99. The HVAC system controls heating and cooling zones 98, 99 withautomatic valves 100, 106, 108 that selectively targets zones with ventsand louvers 97, 105, 109, 110, and its method of operation is to beunderstood by a person skilled in the art. This diagram is forillustration only and is not intended to limit the embodiment to aparticular design.

The air supplying duct 101 takes fresh air through an intake pipe forthe furnace or boiler 104, while the exhaust duct 102 allows the furnaceor boiler 104 and heat pump 103 to exhaust air. Air is drawn into theheat pump 103 from any of the selected rooms and ventilated into any ofthe selected rooms as previously described operations require.

FIG. 9B illustrates a simple retrofit method of home installation in atwo floor house. This method introduces a low cost option forinstallation which does not require professional assistance.

The Room-to-Room heat pump 118 is positioned so as to interface betweenboth the upper level 112 and the lower level 113. In this embodiment,the user could drill a hole through the floor 114 to accommodate theducts 118 and 116 and forms a connection between the home levels.Alternatively, smaller holes could be drilled through the floor to passtubing of refrigerant that run between a condenser on one floor and anevaporator on the other floor. The compressor to force the movement ofthe refrigerant could be located on either floor.

To warm the upper level 112, the device draws air from the lower level113 through vent 118 into the heat pump 115. The upper level 112 iswarmed with air from vent 117, while cool air is exhausted into lowerlevel 113 through exhaust 116.

The same device installed as depicted may also be used to warm the lowerlevel 113 or provide cool air to either level 112 or 113. To cool upperlevel 112, air is drawn into the heat pump 115 through vent 118. Coolair is ventilated into area 112 through vent 117, while warm air isexhausted outside.

FIG. 10 diagrams the operation of the air curtain embodiment of theRoom-to-Room Heat Pump invention. As illustrated, the invention is inthe cooling season mode while the upper floor is occupied. The aircurtain is an advantageous feature because areas of the home are to bemaintained at different temperatures, which may cause air to rise orsink along the stairs according to which area is warmest. As this iscounter to the operational goals of the Room-to-Room Heat Pump, the aircurtain prevents such motion.

A fan 122 is installed in the floor at the top of the stairs 120. Agrate 121 is installed above the fan 122 so that occupants may walkabove it safely. The operation of the fan 122 causes the air above it toform eddies as shown in 123, thus preventing the free flow of air to orfrom the lower level 119.

In a forced hot air heating system, as seen in FIG. 11, the ductwork isalready in place to return the heated air in the room through theheating system's hot-air ductwork 136. There is already a fan in thefurnace 134 for moving the air to the room that is calling for heat. Acondenser 133 can then be added to the furnace 134 after the fan so thatthe fan can take the heat from the condenser 133 and send that heat tothe rooms. Additional logic in the furnace control circuit runs the fanbut does not fire the furnace 134 so that the heating can be done solelywith the condenser 133. Should additional heat be required beyond thecapabilities of the condenser 133, then the furnace 134 itself cansupplement the heat from the condenser 133. The compressor 132 islocated near the furnace 134. In the summer, this condenser 133 can berun in reverse, becoming an evaporator, thus supplying cooling to therooms via the ductwork 136.

The compressor 132 is located in the basement so that the heat from thecompressor can be used in the heating of the house in the winter. In thesummer, large duct with a fan could be used to expel the excess heatfrom the house. The compressor 132 should be in an insulated enclosurein the basement so that the heat can be controlled.

Existing ductwork 136 in the forced hot air system is used so as tomaximize comfort in the occupied rooms.

The evaporator 131 is supplied by tubing 140 containing aChlorofluorocarbon (such as Freon), a Hydrochlorofluorocarbon, aHydrofluorocarbon or similar refrigerant. This refrigerant cyclesthrough the tubing 140, 139 to an evaporator 131. The evaporator 131could be located in the portion of the house where the heat is beingrecovered. Alternatively, ductwork could take the heat from the roomswhere the heat is being recovered to a central evaporator, perhapslocated near the furnace 134, and then the cooled air is returnedthrough separate ductwork. The evaporator 131 is also known in theindustry as a mini-split direct expansion (or mini-split DX) unit.

The separate ductwork for the heat pump does not need to be of the samesize as the normal ductwork, as there is no need to maintain comfort inthe unoccupied rooms (although the quicker it is extracted, the lessloss occurs through the walls).

Placement of the ductwork for heat extraction, or alternatively thelocation of the evaporator 131, should be in a room or an area of thehouse with maximum exposure to the external weather. This could be anarea with 2 or 3 outside walls and perhaps a roof exposure. Or it couldbe an area with a large number of windows, or that is poorly insulated.The goal is to extract the heat from this area before it is lost throughthe walls. In the summer, this may be a room with a southern exposurewith many windows that will be quickly heated by the sun.

In an alternative embodiment, the heat extracted could be stored in abig heat sink in the basement, as described above and in FIG. 6. Thisheat sink would need to be heavily insulated to minimize heat loss.

FIG. 12 shows a two story house with two heating units, one in the attic164 and the other in the basement 134. The reference numbers in thebasement units are the same as used in FIG. 11 as the devices are thesame. The difference between FIG. 11 and FIG. 12 involve the equipmentin the attic.

In FIG. 12, the coolant from the compressor 132 moves through the tubes140 to an evaporator/condenser unit 163 in the attic. When in heat pumpmode, the heat is moved between evaporator/condenser units 163 in theattic and the evaporator/condenser unit 133 in the basement. The airarrives at the furnace 164 from the return vent 167 through the returnducts 165. The furnace 164 may also include an air conditioning unit.When heating the second floor, the furnace 164 may run the burner tosupplement the heat from the condenser 163.

In an alternative embodiment, ductwork is used to move air between theunits in the attic and in the basement instead of coolant. Thisembodiment can be seen in FIG. 16.

FIG. 16 shows the heating system utilizing one embodiment of the currentinvention on a two story, two zone home with a single heating plant 208.In this figure, the air enters the heating system through the returns,206 for the first floor and 204 on the second floor. The air flowsthrough the ductwork 207 and 205 to the heating plant. The return airfrom the second floor flows from the ductwork 205 into the heatexchanger 209 and then into the supply ductwork 200 and to the supplyvents 201. The return air from the first floor flows from the returnductwork 207 into the heat exchanger 210 and then into the supplyductwork 202 and to the supply vents 203.

The heat exchangers 209 and 210 perform multiple functions, which aredescribed in further detail below. The heat exchangers 209 and 210 haveblowers to move the air through the ductwork and have coolant coils forperforming the function of a condenser or an evaporator, transferringheat either from or to the coolant in the coolant tubes 212. The coolantis moved through the system with a compressor 211. The coolant tubes 212include valves that permit the flow of coolant to be reversed, so thatheat can be transferred from either the second floor heat exchanger 209to the first floor heat exchanger 210 or in the other direction. Thisallows heat to be extracted from one floor and transferred to the otherfloor. In addition, the heat exchangers 209 and 210 allow the air to beheated or cooled by the heating plant 208.

The compressor 211 in FIG. 16 (and possibly in the compressors 132 inFIGS. 11 and 12) could be located in the basement of the house,conserving the heat from the compressor 211 in the building. Ductworkmay be necessary in the summer to vent this heat outside of the housethrough the use of louvers and valves. In certain situations there areadvantages to maintaining thermal isolation between some of the variouscomponents of the system. Alternately, a water cooled compressor couldbe used, and the heat exchanged into a heat exchanger 209 and 210 in thewinter or to a cooling tower in the summer.

There are many combinations of heating and cooling the first and secondfloors in the summer and winter to add or subtract heat from an area ofthe house, each of these combinations are easily understood by one ofordinary skill in the art given the figures and specification of thepresent invention.

To achieve maximum flexibility in the transfer of heat between any tworooms, a multi-condenser, multi-evaporator system is shown in FIG. 13.Multiple condensers 154 a-d and evaporator 154 a-d units (also known asmini-split DX) are installed throughout the house, including one outsidein some embodiments. Since this system is flexible and can be run ineither direction, each unit 154 a-d can function as either a condenseror an evaporator, depending on which direction the refrigerant isflowing. The condenser/evaporator units 154 a-d also include a fan tomove the air across the coils. The compressor 150 pushes high pressurerefrigerant into a dual-input, dual-output solenoid valve 151 that cansend the high pressure refrigerant from the tube 155 to either the tubefor manifold 152 a (tube 157) or manifold 152 d (tube 158). A controlsystem determines the state of the solenoid and thus which direction therefrigerant flows. If it goes to tube 157, then the refrigerant will goto manifold 152 a (these manifolds are known in the industry as solenoidvalve manifold units). This manifold 152 a has four ports, although oneof ordinary skill in the art could envision using any number of portsfor the manifolds 152 a-d depending on the size of the system. Manifold152 a has the four ports controlled by the control system so that onlyone port is open at a time (however, a more sophisticated control systemmay allow multiple ports to be opened simultaneously to allow for theremoval or insertion of heat to multiple rooms simultaneously). Say thatit is desired that the room containing evaporator/condenser 154 a beused to remove heat. Then the first port on manifold 152 a is opened toallow the refrigerant from 157 to flow through port 1 on manifold 152 athrough junction 153 a and then through tubing through the walls of thehouse to evaporator 154 a which is performing the evaporation functionin this example. The refrigerant the flows out of evaporator 154 a backthrough the tubes in the walls into junction 153 b. Port 1 on manifold152 c is opened by the control system to receive the refrigerant (port 1on manifold 152 d must be closed to prevent the refrigerant from goingstraight back to the compressor 150). The refrigerant is then piped tomanifold 152 b for distribution to a condenser 154 a-d. Say that it isdesired to add heat to the room containing condenser 154 d, then thecontrol system will open port 4 on manifold 152 b, allowing therefrigerant to flow to junction 153 g and through the walls of the houseto condenser 154 d. The refrigerant then flows out of the condenser 154d, through the walls of the house to junction 153 h, and into manifold152 d, port 4. From manifold 153 h, the refrigerant flows through tube158, through the dual-input, dual-output solenoid valve 151 and thenthrough tube 156 and back into the compressor 150. One of ordinary skillin the art can determine other combinations to move heat in or out ofany room with a condenser/evaporator 154 a-d. A control system for theheating/cooling system coordinates a series of valves on the refrigeranttubing between each of these units, allowing heat to be extracted orplaced at any one of the condenser or evaporator units at any point intime.

While the tubing connecting the compressor 150 with theevaporator/condensers 154 a-d seem complicated, in one embodiment it isenvisioned that this could be a single manufactured part 159 coveringthe dual-input, dual-output solenoid valve 151, the manifolds 152 a-d,the junctions 153 a-h and all of the interconnecting tubing and solenoidcontrols. While FIG. 13 shows a 4 evaporator/condenser 154 a-d system,one of skill in the art could understand how to build a similar systemwith any number of evaporator/condenser units 154 a-d. The installerwould then need to connect tubing 155 and 156 to the compressor 150 andrun pairs of tubing from the part 159 to each evaporator/compressor 154a-d located in various rooms in the house.

A control system operates the system in FIG. 13, controlling thedirection of the refrigerant so that one compressor/evaporator 154 a-doperates as an evaporator, taking heat out of a room, and anotheroperates as condenser adding heat to a room. In a more complicatedsystem, it is envisioned that the control system could control allmultiple compressors or evaporators in the system.

With this system, heat can be transferred in or out of a number ofrooms. Additional movement of heat can be facilitated if one of thecondenser/evaporators 154 a-d is located outside.

Note that this system could be simplified if the condenser/evaporator iscoupled to a typical heating system and the heat (or cooling) isdistributed through the normal ductwork, as see in FIG. 10.

Description of Room-To-Room Operation Night Operation—Heating SeasonMode

At a certain time determined either by the user or automatically, theRoom-to-Room Heat Pump activates. For instance, in manual setup mode theuser might turn on the Room-to-Room Heat Pump and adjust the thermostatdown to 40° F. at 10:00 PM.

The heat pump acts upon two locations. The first is referred to as the“Living Area”. This area is made up of rooms that are unoccupied in thenight, such as the living room, kitchen, and dining room. In night timeoperation, the heat pump rapidly cools down the air in the Living Areato the predetermined Cold Temperature, which is either controlled by athermostat on the heat pump or by a central household thermostat. Thesecond area is referred to as the “Sleeping Area”. This area is made upof the bedroom and other areas likely to be occupied during the night,such as the bathroom. At the same time the device is cooling down theliving area, it begins to warm the sleeping area. Warm air is broughtinto the sleeping area to bring it up to a comfortable temperature andmaintain that temperature as heat is lost throughout the night. Thiskeeps the homeowner comfortable without wastefully heating unoccupiedrooms.

The effect of the Room-to-Room Heat Pump is that the average temperatureof the house may be substantially lowered without negatively impactingthe homeowner's comfort. For example, the home may be maintained at anaverage temperature of 55° F., which would ordinarily be uncomfortablycold. The action of the Room-to-Room Heat Pump maintains the occupiedareas of the home at 70° F. by drawing heat from the unoccupied areas,whose temperatures subsequently drop. As the temperature of theseunoccupied areas decreases, the difference between their temperaturesand the outdoor temperature is diminished. This decreases the rate ofheat lost out of the home. The net effect is the same as if the homewere maintained at the average temperature.

According to the United States Department of Energy, every degree ofsetback over an eight hour period equates to an annual heating billsavings of approximately 1% when used consistently (U.S. Department ofEnergy. “Thermostats”, Nov. 26, 2013. Date of Access: Jun. 20, 2014.<http://energy.gov/energysaver/articles/thermostats>.) Maintaining theaverage temperature at 55° instead of 70° F. would save 15% annually onheating. Moreover, the savings are actually greater than 1% per degree,as the heat pump can act during the daytime as well as night.

In the course of its use, the operation of the Room-to-Room Heat Pumpitself warms the house to some extent. Due to the laws ofthermodynamics, this thermal energy will be approximately equal toelectrical energy drawn from the grid. Any heat lost from the home netof the heat pump's waste heat must eventually be replaced by the furnaceor boiler. Because the occupied areas of the home are maintained at ahigh temperature, heat loss from the house works to decrease thetemperature of the unoccupied areas. With each cycle of day-night, theunoccupied area is becoming progressively colder. Finally, theunoccupied area will fall below the minimum set point, thus triggeringthe furnace or boiler to activate.

As part of their normal operation, heat pumps remove humidity from theair. This may be problematic in the wintertime, when humidity levels arealready quite low. In one embodiment of the invention, the water removedfrom the air is collected and added back into the air at a later stage.By adding a humidifying step to the process, the dehumidificationeffects inherent to heat pumps are counterbalanced.

Daytime Operation—Reversing

The heat pump's operation throughout the night keeps the occupied areasof the house warm at the expense of the unoccupied areas. While thissaves a substantial amount of energy, it leaves those unoccupied areastoo cold for user comfort. To address this situation, the Room-to-RoomHeat Pump invention may be reversed. The reversibility means that it canoperate in both directions: removing or adding heat to each room.

The reversing mode is enabled by means of a solenoid valve built intothe device. Solenoid valves are operated electronically, so that thedevice can send a signal when it is entering reverse mode. This causesthe solenoid valve to flip, reversing the direction of flow of thecoolant fluid in the heat pump. Persons skilled in the art will befamiliar with the operation and purpose of a solenoid valve.

When the refrigerant fluid flows in reverse, the device operates in theopposite way as in heating season mode. It removes heat from thesleeping area and adds it to the living area. The time required tocomplete the reversal in the morning depends on factors such as the sizeof the device and the size of the unoccupied areas. Industry studiesshow that it takes approximately one hour to bring the air back to theset point following night time setback, so the device will need toreverse about an hour before the user gets out of bed. It should notcompletely reverse the area temperatures, but rather bring them intoequality. If the device were to completely reverse the temperatures, thesleeping area would be excessively cold when the user awoke.

If the user finds the average home temperature to be too cold in themorning, the user may program the thermostat to increase to a morecomfortable level during the morning hours, then decrease again afterthe user leaves for the day.

In one embodiment, the schedule of the user is known by the system andthe system moves the heat to the area that the user is going to beforehe arrives. For instance, if the user typically awakes at 7 AM, the usercould program a calendar based thermostat so that the system will startat 6:30 AM to move the heat from the bedroom to the kitchen so that thekitchen is warm when the user arrives. Additional heat from thetraditional heating system may also be used to heat the kitchen tosupplement the heat movement.

Alternatively, if the user finds that he desires both the bedroom andthe kitchen to be warm at 7 AM, the traditional heating system could beused to heat the kitchen from 6:30 AM until 7:30 AM, and then utilizethe present invention to move the heat from the bedrooms back to thekitchen.

The calendar based thermostat could be as simple as a set-backthermostat or as complicated as a device that interfaces with the user'scalendar app on a smart phone or personal computer. Furthermore, the appor the thermostat could review the user's history of sleep and waketimes and predict when the heat should be transferred.

If this cold temperature is unacceptable to the user, he may choose toengage the home furnace or boiler in addition to the heat pump. Thiswould then bring the cold rooms' temperatures up to an acceptable levelby the time the user is inhabiting them. Leaky or poorly insulatedhomes, too, may need to activate the furnace or boiler in the morning.This is necessary when too much heat has escaped the home. As the homeloses heat, its average temperature continues to drop. If one room'stemperature is kept at room temperature while the furnace or boiler isnot engaged for a significant period of time, the unoccupied room'stemperature will drop at twice the rate as usual. This may become anissue over repeated reversals. As a general rule, the unoccupied room'stemperature should not drop below 40° F., as temperatures lower thanthis may result in icing of the heat pump's coils. This decreasesefficiency, because the heat pump thaws its coils with electricity.Therefore, the home thermostat is set no lower than the icingtemperature of the realized device.

Method of Installation

There are two methods of installation and integration conceptualized forthe Room-to-Room Heat Pump. The method chosen will be a function of costand the home's infrastructure. The total integration method may be idealfor new home construction, while the retrofit method accommodatesexisting homes.

A. Retrofit Method

The first method of installation is a retrofit method. The Room-to-RoomHeat Pump is installed in such a way that it can interface with eachhome level, which may require a hole be cut through the upper levelfloor. The heat pump may intake air directly at the pump body, or it mayuse extended ducts strategically located for ideal unit operation.

The ducts have different intake points which are activated sequentiallydepending on the method of usage and time of day. In heating seasonmode, the intake point closest to the unoccupied room's ceiling would beactivated at night. The point closest to the floor of the occupied roomwould be used for output. During the daytime, the intake point closestto the ceiling of the sleeping area would be activated, while the pointclosest to the floor of the living area would be used for output. Thismethod allows the device to preferentially select the specific locationsin rooms that are likely to have the highest concentration of heat. Therationale for point selection is based on the principle that hot airtends to rise.

This method of installation may require the drilling of a hole in thefloor of the upper room(s) and ceiling of the lower room(s) to enablethe device to interface between levels of the house. The holes aresealed to eliminate air leaks, which carry significant heat transferalong with them.

B. Integration with Existing System

The Room-to-Room Heat Pump can be integrated or built into the home'sHVAC system. When the home has multiple heating and cooling zones, thedevice can then selectively target rooms to heat or cool through theheating vents in the respective rooms through the use of controllableductwork. The controllable ductwork would consist of louvers and valvesused to create thermal isolation between various components of thesystem when it is advantageous. The heat pump can be integrated into theHVAC ductwork in such a way that it does not interfere with theoperation of the furnace. In one embodiment, it is built into theductwork of the existing furnace or boiler system.

Another option would be a unique method of using an air-source heatpump. Some homes currently use heat pumps as the sole source of heatingfor the home. These heat pumps extract heat from the outside air to warmthe house. The heating systems using these outdoor heat pumps can bedesigned in such a way that the heat pump can also move heat from roomto room. This method requires multiple heating and cooling zones, whichgives the device excellent control over the temperature of rooms withinthe house.

In another embodiment, multiple condenser and evaporator units areinstalled throughout the house, including one outside. A control systemfor the heating/cooling system coordinates a series of valves on therefrigerant tubing between each of these units, allowing heat to beextracted or inserted at any one of the condenser or evaporator units atany point in time. In this embodiment, a central compressor has manifold(a distribution device attached that splits the tubing of refrigerantinto multiple tubes, each tube equipped with a solenoid to control wherethe refrigerant goes). A control system allows one solenoid to open,allowing the refrigerant to flow through tubing to an evaporator in theroom where heat is to be removed. The tubing on the other side of theevaporator returns to a location near the compressor. Here, a secondmanifold (or set of solenoids and distribution device allow therefrigerant to flow back into a common tube) collects the tubes fromeach of the evaporators and then sends the refrigerant into a manifoldthat manages the distribution to the various condensers where heat isrejected. On the other side of the evaporators, a fourth manifoldcollects the low pressure refrigerant from the evaporators. The designalso allows for the system to be run in both directions, so that eachcondenser and evaporator could function with the other functionality.Each condenser/evaporator includes a directional fan to move the air inthe room across the coils. The fan will take warmer air from the ceilingthrough the coils and direct the conditioned air towards the floor. Withthis system, heat can be transferred in or out of a number of rooms.Additional movement of heat can be facilitated if one of thecondenser/evaporators is located outside to collect or disperse heat.

Heat pumps used to heat homes typically have backup electricalresistance heating. These come online when the heat pump is for somereason unable to supply the necessary heat to the house, such as whenthe outdoor temperature is too low. Electrical heating has a COP of 1, athird the value of a typical heat pump, so using the backup rapidlyincreases costs. Therefore, integrating the Room-to-Room Heat Pumpmethod into an air-source heat pump system can decrease energy costs bycutting reliance on backup heating. The heat pump is controlled by analgorithm that for instance moves heat from unoccupied areas to sleepingareas rather than calling on the backup heater.

The home integration installation method has advantages over theretrofit method. Improved integration into the ductwork decreases thevisible footprint of the device. The device is also installed away fromthe sleeping area, so users cannot hear it. In addition, the systemintegration method of installation eliminates the need to drill holesinto existing walls and/or flooring, which must be done carefully toavoid creating thermal leaks. However, this method is likely moreexpensive than the retrofit method, requiring professional installation.It would therefore be a good candidate for new construction orremodeling, when it can be designed into the system.

In contrast, the retrofit method is an affordable alternative forhomeowners looking to reduce their heating bills. Well-positionedinstallation will minimize the visual and auditory footprint of thedevice.

Thermostat Control

The Room-to-Room Heat Pump device makes use of no less than twothermometer readings to operate successfully. A thermometer located ineach of the control zones is required, as the device needs to be awareof when either of the unoccupied or occupied rooms is too cold or toowarm. The temperature readings could come from existing thermostats, asin the case of total system integration installation method.Alternatively, small digital thermometers may be located on the ducts inthe controlled rooms. These thermometers may be wirelessly connected tothe central device, or connected with a communication circuit.

In one embodiment, an outdoor temperature reading is also used for thecooling season mode. This may be derived by placing a digitalthermometer outside of the house, or alternatively by making use of aninternet connection to find local weather conditions. In anotherembodiment of the cooling season mode, the home heating pump does notinterface with the outdoor air at all, and instead expels warm airdirectly into the unoccupied area. In this case, only two thermometersare needed.

In one embodiment, the Room-to-Room Heat Pump is controlled with amanual thermostat. The thermostat has temperature settings for theoccupied and unoccupied zones. For each additional controlled zone, anadditional thermostat setting is needed. As the room temperatures fallabove or below the desired temperature, the heat pump activates or shutsoff depending on the mode of operation.

Another embodiment of the invention has a programmable thermostatcontroller, which would enable the user to change the temperatures at apredetermined time. This allows the user to choose when the heat pumpactivates and at what time it reverses according to his preferences.

In another embodiment, the Room-to-Room Heat Pump can interface with thecentral thermostat. The thermostat can call upon the Room-to-Room HeatPump based on user programming. It can also coordinate use of theRoom-to-Room Heat Pump and the furnace or boiler in order to minimizeenergy usage.

In another embodiment, the heating system as a whole can be controlledby a “smart” programmable thermostat. If the thermostat has wirelessconnectivity, a mobile app enables the user to activate the deviceremotely. As the thermostat learns the homeowner's habits, itselectively calls upon the Room-to-Room Heat Pump to guide heat fromroom to room without being called upon to do so. In addition, the heatpump may detect room occupancy automatically. In one embodiment, it doesthis by means of motion detectors placed in the controlled rooms. In analternate embodiment, remote sensing devices tethered to a user-helddevice such as a smartphone to determine the user's location. Bydetermining the user's location, the Room-to-Room Heat Pump may directheat where it is needed in response to a user's movements.

FIG. 17 shows the logic for the systems operation during the wintermonths. This logic diagram does not go to the level of specificityinvolving a few degree hysteresis, but someone sufficiently skilled ofthe art could easily apply hysteresis concepts to avoid heat pumpcycling. Element 213 denotes the initiation of the system along with theboot up of all sensors. Once the system is initialized 213, thethermostat for the space in question compares the actual temperature ofthe space with that of the setting on the thermostat 214. If thethermostat determines that the actual temperature is significantly (acouple degree hysteresis is used to avoid cycling) below the temperaturesetting on the thermostat it moves on to element 215. If the thermostatdetermines that the actual temperature is not significantly (a coupledegree hysteresis is used to avoid cycling) below the temperaturesetting on the thermostat it moves on to element 214 a. 214 a causes thethermostat to check to see if the space is significantly above thetemperature setting on the thermostat. If the temperature is notsignificantly above the setting, element 216 is called and no actionsare taken, leading the system back to 214. Alternatively, if 214 areturns that the space is hotter than desired, 217 is called and asearch is run to see if one of the other spaces in the home is callingfor heat. If element 217 comes back negative, 216 is called. However, ifelement 217 comes back affirmative, the excess heat in the space ispushed by the heat pump to the space calling for heat 219.

Returning to element 215, when 215 is called, a check is made to see ifany other zones have passed element 214 a. If this is the case, element219 is once again called. In this instance however, the space inquestion is the space being heated, not the space supplying the heat. Inthe event no other zones have passed 214 a, element 218 is called,supplying heat to the zone in question using a traditional boilersystem. Both element 218 and element 219 proceed directly to element 220upon being called. Element 220 causes the thermostat to run anadditional check to see if the space being heated still requiresadditional heat to reach the desired temperature. As long as it does,element 215 is once again called. When it does not, heating processesare stopped 221, and the process begins again at 214.

FIG. 18 describes a similar system to FIG. 17 but includes the addedcomponent of the heat sink discussed in the Method of InstallationSection. This logic diagram does not go to the level of specificityinvolving a few degree hysteresis, but someone sufficiently skilled ofthe art could easily apply hysteresis concepts to avoid the known issueof heat pump cycling. Element 222 denotes the initiation of the systemalong with the boot up of all sensors. Once the system is initialized222, the thermostat for the space in question compares the actualtemperature of the space with that of the setting on the thermostat 223.If the thermostat determines that the actual temperature issignificantly (a couple degree hysteresis is used to avoid cycling)below the temperature setting on the thermostat it moves on to element226. If the thermostat determines that the actual temperature is notsignificantly (a couple degree hysteresis is used to avoid cycling)below the temperature setting on the thermostat it moves on to element224. Element 224 causes the thermostat to check to see if the space issignificantly above the temperature setting on the thermostat. If it isnot above the set value, 225 is called and all heating processes arestopped, and 223 is called again. If element 224 yields positiveresults, 227 is called, looking to see if another space is calling forheat. If element 227 finds that no other spaces are calling for heating,229 is called (otherwise 230 is called). 229 checks to see if the heatsink component is able to store the excess heat present in the space.The heat sink is considered able to store the excess heat if it iscurrently below a maximum temperature determined to be most efficientfor heat storage. If it can store the excess heat, element 233 is calledand the heat is pumped to the sink and then the system returns to 224 tosee it another room needs heat. If the heat sink cannot store the excessheat, element 225 is once again called. Returning to element 226, arequest is made by the thermostat to see if any other spaces have excessheat. If another room does have excess heat 230 is called. When element230 is called heat is pumped directly from the unused room to the roomthat requires heating. If element 226 comes back negative, an additionalcheck is run to see if there is heat that can be used currently residingin the heat sink 228. The heat sink will be considered to have heat ifit is above a minimum temperature determined to be the most efficientfor heat storage. If the heat sink has heat that can be used by thespace, element 231 is called, pumping the heat from the heat sink intothe room. If the heat sink does not have excess heat, element 232 iscalled, which sends a request to the boiler to heat the room inquestion. When elements 230, 231, and 232 are called, the system beginsto check the thermostat to see if the space requires additional heating234. If the space does require additional heating, the program returnsto 226 and rechecks to see which heat source to use to continue heating.On the other hand, when the space no longer needs additional heating, astop command is issued 235 and the program returns to 223.

Thermal Storage

An alternate conception of the Room-to-Room Heat Pump includes theability to store heat. This can maximize energy savings in situationswhere, for instance, only a small amount of heat is required in thesleeping area. Rather than allowing the unoccupied areas to lose thermalenergy to the ambient atmosphere, the device stores thermal energy in astorage tank. Thermal energy from indoor air is stored in a thermal tankby means of a heat exchanger wrapped around for instance a water-filledtank. If the tank or refrigerant loop is well insulated, it can storelarge amounts of heat with a minimal loss rate.

The device separates the task of removing heat from the unoccupied roomfrom adding heat to the occupied room. If heat is continually removedfrom a large room and added to a smaller room, it may cause the room tobecome uncomfortably hot, thus triggering heat pump shut down. However,this allows the unoccupied room temperature to decline more slowly,which cuts into energy savings. Decoupling the cooling of the unoccupiedrooms from the warming of the occupied room or vice versa eliminates thepreviously described problem. The same method may be used in coolingseason mode, with a thermal storage tank being cooled rather thanwarmed.

FIG. 14 denotes a system of two tanks and a heat exchanger used as aheat sink to aid the heat pump. The system relies on a hot tank 170 anda cold tank 169. Both of the two tanks would be as thermally isolatedfrom the surroundings as is feasible. The advantage of the two separatedtanks is the ability to manipulate the temperature delta in the heatexchanger and the heat pump in order to optimize the required resourcesfor the various heating processes the tanks take part in. The size ofthe two tanks varies with the requirements of the home they areinstalled in, some calculations related to this can be found in the“water heat sink size calculations”. In addition to the tanks, a heatexchanger 172 operates to exchange heat from the tank system to the heatpump coolant filled tubes, (or in a separate iteration, directly withthe air). In a heating operation the two way pump 171 would suck waterfrom the cold tank 170, run it through the heat exchanger 172 and intothe hot tank 169. In this operation, most commonly occurring duringwinter months, the system would be acting as an condenser. Conversely,in a cooling process, water would be pulled in the opposing direction bythe two way pump 171, in this situation it would be operating as aevaporator. Worth noting is that the heat exchanger 172 utilizes highsurface area and conductive materials to aid in the efficient transferof the heat. When running through the system, steps must be taken toavoid freezing in the water tanks. There are multiple options to avoidfreezing, one of which is adding salt to the water, another is addingantifreeze to the water. Additionally, the pump will help to avoidfreezing because the water is moving.

The hot tank 170 will lose heat over time if not replenished. In thissituation, eventually the water in the hot tank 170 will become cold.Once the temperature in the hot tank 170 falls below a set point, all ofthe water in the hot tank is pumped back to the cold tank 169. In thecooling season this is reversed.

FIG. 15 shows a concrete heat sink used to store excess heat pulled fromunused rooms in the home. Note that concrete is just an example; anycombination of solid materials with high heat capacity would besuitable. The system relies on concrete structures 175 embedded in apipe 174 that acts as a heat exchanger. Because of the nature of theheat sink, one side of the concrete will be warmer than the other, in aheating process air will be drawn from the cold end of the concretetowards the hot end, and then in a cooling process the opposite willoccur. Specific attention should be paid to the concrete in thisiteration, steps must be taken to avoid cracking, or damage due to thethermal expansion of the concrete. The main advantage of the concreteiteration of the thermal storage tank is the potential for it to take upless volume in the home, it also has a major disadvantage of beingdifficult to disassemble in the event of maintenance issues.

One of the advantages of utilizing a thermal storage unit is the abilityfor a user to engage in off-peak heating. Currently, energy prices arenot dependent on the time of day, but in certain markets the idea hasbeen brought up before. In a situation where using electricity at nightis cheaper for a homeowner than during the day, off-peak heating wouldsignificantly reduce energy costs. The process of off-peak heating wouldhave two steps; the first of these is during off-peak hours the heatpump would work to heat the thermal storage tank to prepare for requiredheating during the day. Then, later during on-peak hours the hotreservoir would run through the heat exchanger, helping to heat thehouse when energy costs are higher.

An important factor for both the concrete and the water iteration of theheat storage unit concept is the relationship between the size of thestorage unit and the required size of the heat pump. The nature of theprocess heat pumps utilize in order to facilitate heating or coolingresults in decreased efficiency of the heat pump as the temperaturedelta between the inlet and the outlet of the heat pump increase. As thesize of the storage unit decreases, it takes a larger temperature deltato store the same amount of heat (due to conservation of energy), thisin turn requires a more powerful heat pump to be able to complete theprocess. In the opposite case, as the heat sink size increases, therequired temperature delta to store the same amount of energy decreases,also allowing for a smaller heat pump. Striking the balance between heatsink size and heat pump size will vary with the thermal footprint of thehome.

Air Curtains

In the process of maintaining two areas of a home at differenttemperatures, a large thermal gradient is created. Thermal gradientscause heat to move from area of high temperature to low temperature. Inareas of a home where volumes of air at different temperaturesinterface, the previously described thermal gradient can cause a rapidtransfer of heat between the two areas. To prevent this transfer ofheat, an embodiment of the invention creates curtains of air at thermalloss points such as staircases. This curtain creates vortices in the airwhich impedes its flow, thereby arresting the transfer of heat. Forexample, in cooling season mode the occupied area may be the upperfloor. Because the upper floor is kept at a lower temperature than thelower floor, the air from the upper floor will tend to flow down thestaircase. The air curtain pushes back the air, preventing it fromflowing freely. In this case, heat is still exchanged at thewarm-to-cold interface, but at a much slower rate than if the air couldflow unimpeded.

In one embodiment, the curtains are created by positioning the air ventsof the invention in such a way that the normal operation of the devicecreates vortices in the air which prevent the free air flow betweenoccupied and unoccupied areas.

In another embodiment, fans placed in the floor at the designatedthermal interface points create the previously mentioned thermal curtaineffect. The fans or vents are integrated into the floor such that theydo not create a tripping hazard.

Mechanical Distinctions

One embodiment of the Room to Room Heat Pump system contains four majormechanical distinctions from a traditional two zone heat pump system.These mechanical distinctions taken together describe an entirely newand distinct piece of hardware. A traditional two zone heat pump uses asimple fan to direct airflow in the home, allowing only one direction ofairflow. Additionally, a normal heat pump contains only one largerefrigerant coil, which is sufficient to fulfill simplistic heating orcooling processes. A traditional two zone heat pump system also containssimplistic ducting, with only one inlet and outlet to the heat pump todraw air from/too. Lastly, simplistic valving is present in atraditional heat pump system, with no need for reversible refrigerantflow there is no need for advanced valving.

This embodiment of the Room to Room Heat Pump differs from thetraditional heat pump system regarding fan use. This room to room heatpump may use two axial flow fans, in contrast with the simple onedirectional single fan design of a traditional heat pump. The simple onefan design uses a fan positioned at the outlet of the heat pump todirect flow throughout the house. An axial flow fan can be operated inboth the forward or backwards direction effectively, allowing for it tobe effectively reversible. The use of multiple fans with reversible flowmay be useful in the implementation of the room to room heat pump inthis embodiment due to its need for reversible airflow in multiplezones. Note that each fan would correspond to a different andindependent zone, so as not to interfere with one another.

The use of a single, long refrigerant coil is one of the definingfeatures of a normal heat pump. This embodiment of the Room to Room HeatPump uses two smaller refrigerant coils, instead of the traditional onecoil system. The two separate refrigerant coils allow for multipleindependent thermal processes to be occurring at one time. Havingmultiple independent thermal processes occurring at one time allows forthe simultaneous cooling of one space while also heating another.

In a multi-zone system for home heating/cooling, one single inlet andoutlet duct is used to connect to the heat pump. The two ducts separate,and allow for one zone to be subjected to a thermal process whileanother is left be, or allows for both zones to be subjected to the samethermal process at once. In this embodiment of the heat pump system, twocompletely separated duct systems may be used. Two separate inlets andtwo separate outlets are used for maintaining the distinction betweenthe two zones. This is to allow independent airflow for multipleconcurrent operations of the heat pump.

Normal heat pumps use simplistic valving in order to control refrigerantflow in the compressor for thermal processes. Because of the complexityof the new system, more complex valving is used in this embodiment inorder to fit the needs of the system. This valving of increasedcomplexity is used because the new system uses a reversible refrigerantflow from the compressor. Reversible refrigerant flow allows for thecompletion of multiple independent operations.

One additional mechanical component to the room to room heat pump is ahousing for the heat pump and compressor that can be thermally isolatedfrom the house or the outside when it is useful. In the winter months,thermal isolation from the house would not be useful, but thermalisolation from the outdoors would be. In the summer months, conversely,the system would be thermally isolated from the home and thermallylinked with the outdoors. Note that in the summer months indoor air willbe recirculated by the heat pump for cooling processes, and heatgenerated by the heat pump would be pumped out of the house

Calculations

There are several technical issues which were addressed to validate thefeasibility of this invention. The first technical issue is whetherthere is enough heat available within the house to maintain thetemperature of the occupied area. Air itself has a low thermal capacity,meaning it doesn't store much heat energy. However, a number of otherhousehold materials contain significant amounts of heat. The followingsection evaluates the heat available for transfer in a representativehouse.

The second task is to evaluate the savings when the home heating pump isinstalled. This value is likely to vary substantially based on a numberof factors, such as home size and fluctuating energy costs, so arepresentative home is used. The economics of specific homes will beevaluated by the installer.

Thermal Capacitance Calculations Summary of Findings

There is sufficient heat available for the heat pump to deliver 6270Btu/hr. With a typical heat pump COP (Coefficient of Performance) of 3,this draws 613 W. It removes 4180 Btu/hr from the source room in thesame time period. This is substantial enough to heat the sleeping areaand lower the living area temperature to 40° F.

Task: Estimate the thermal storage in a living room, accounting forwalls, floor, ceiling, and furnishings.

$\begin{matrix}{\mspace{20mu} {{{\underset{\_}{Assumptions}\mspace{20mu} {{1.\mspace{14mu} {Weight}\mspace{14mu} {of}\mspace{14mu} {furnishings}} = {200\mspace{14mu} {lb}_{m}\mspace{14mu} {wood}}}\mspace{20mu} {{2.\mspace{14mu} c_{p,{wood}}} = {0.48\mspace{14mu} {Btu}\text{/}{lb}_{m}{^\circ}\mspace{14mu} {F.\mspace{20mu} 3.}\mspace{14mu} {Room}\mspace{14mu} {Size}\mspace{14mu} 20^{\prime}W \times 20^{\prime}L \times 9^{\prime}H}}\mspace{20mu} {{4.\mspace{14mu} {Drywall}},{68\mspace{14mu} {lb}_{m}\mspace{14mu} {for}\mspace{14mu} 4^{\prime} \times 8^{\prime} \times {1/2^{''}}}}\mspace{20mu} {5.\mspace{14mu} \text{?}}} = {{0.26\mspace{14mu} {Btu}\text{/}{lb}_{m}{^\circ}\mspace{14mu} {F.\mspace{20mu} 6.}\mspace{14mu} \rho_{wood}} = {45\frac{{lb}_{m}}{{ft}^{2}}}}}\mspace{20mu} {7.\mspace{14mu} {Neglect}\mspace{14mu} {exterior}\mspace{14mu} {wall}}\mspace{20mu} {{8.\mspace{14mu} {Initial}\mspace{14mu} T\mspace{14mu} {of}\mspace{14mu} {interior}},{walls},{floor},{ceiling},{{floor} = {{70{^\circ}\mspace{14mu} {F.\mspace{20mu} 9.}\mspace{14mu} {Final}\mspace{14mu} T\mspace{14mu} {of}\mspace{14mu} {above}} = {40{^\circ}\mspace{14mu} {F.\mspace{20mu} 10.}\mspace{14mu} {Floor}\mspace{14mu} {is}\mspace{14mu} 1^{''}\mspace{14mu} {thick}}}},{{{under}\mspace{14mu} {floor}} + {hardwood}}}\mspace{20mu} \underset{\_}{{Solution}\mspace{14mu} {Steps}}\mspace{20mu} {{1.\mspace{14mu} {Calculate}\mspace{14mu} {interior}\mspace{14mu} {wall}\mspace{14mu} {area}},{ft}^{2}}\mspace{20mu} {{2.\mspace{14mu} {Calculate}\mspace{14mu} {floor}\mspace{14mu} {and}\mspace{14mu} {ceiling}\mspace{14mu} {area}},{ft}^{2}}\mspace{20mu} {{3.\mspace{14mu} {Calculate}\mspace{14mu} {weight}\mspace{14mu} {of}\mspace{14mu} 3\mspace{14mu} {interior}\mspace{14mu} {walls}},{lb}_{m}}\mspace{20mu} {{4.\mspace{14mu} {Calculate}\mspace{14mu} {weight}\mspace{14mu} {of}\mspace{14mu} {ceiling}},{lb}_{m}}\mspace{20mu} {{5.\mspace{14mu} {Calculate}\mspace{14mu} {weight}\mspace{14mu} {of}\mspace{14mu} {floor}},{lb}_{m}}\mspace{20mu} {{6.\mspace{14mu} {Calculate}\mspace{14mu} {energy}\mspace{14mu} {released}\mspace{14mu} {by}\mspace{14mu} {walls}},{floor},{ceilings},{and}}\mspace{20mu} {{furnishings}\mspace{14mu} {to}\mspace{14mu} {the}\mspace{14mu} {room}\mspace{14mu} {between}\mspace{14mu} 70{^\circ}\mspace{14mu} {F.\mspace{14mu} {and}}\mspace{14mu} 40{^\circ}\mspace{14mu} {F.\mspace{20mu} \underset{\_}{Solution}}}\mspace{20mu} {\underset{\_}{{Step}\mspace{14mu} 1}\text{:}\mspace{14mu} {Calculate}\mspace{14mu} {interior}\mspace{14mu} {wall}\mspace{14mu} {area}}\mspace{20mu} {{A\left( {ft}^{2} \right)}_{wall} = {{\left( {20\mspace{14mu} {{ft}.}*9\mspace{14mu} {ft}} \right)*3} = {540\mspace{14mu} {ft}^{2}}}}\mspace{20mu} {\underset{\_}{{Step}\mspace{14mu} 2}\text{:}\mspace{11mu} {Calculate}\mspace{14mu} {wall}\mspace{14mu} {and}\mspace{14mu} {ceiling}\mspace{14mu} {areas}}\mspace{20mu} {{A\left( {ft}^{2} \right)}_{floor} = {{A\left( {ft}^{2} \right)}_{ceiling} = {{20\mspace{14mu} {ft}*20\mspace{14mu} {ft}} = {400\mspace{14mu} {ft}^{2}}}}}\mspace{20mu} {\underset{\_}{{Step}\mspace{14mu} 3}\text{:}\mspace{14mu} {Calculate}\mspace{14mu} {the}\mspace{14mu} {mass}\mspace{14mu} {of}\mspace{14mu} {the}\mspace{14mu} 3\mspace{14mu} {walls}}\mspace{20mu} {{Mass} = {{Area}*{{Density}\mspace{14mu}\left\lbrack {{Drywall}\mspace{14mu} {density}\mspace{14mu} {is}\mspace{14mu} {available}\mspace{14mu} {in}\mspace{14mu} {lb}\text{/}{ft}^{2}} \right\rbrack}}}\mspace{20mu} {M_{walls} = {A_{wall}*\rho_{{dry}\mspace{14mu} {wall}}}}\mspace{20mu} {M_{walls} = {{540\mspace{14mu} {ft}^{2}*\frac{68\mspace{14mu} {lb}_{m}}{32\mspace{14mu} {ft}^{2\;}}} = {1148\mspace{14mu} {lb}_{m}}}}\mspace{20mu} {\underset{\_}{{Step}\mspace{11mu} 4}\text{:}\mspace{14mu} {Calculate}\mspace{14mu} {the}\mspace{14mu} {mass}\mspace{14mu} {of}\mspace{14mu} {the}\mspace{14mu} {ceiling}}\mspace{20mu} {M_{ceiling} = {400\left( {{{{ft}^{2}*\frac{68\mspace{14mu} {lb}_{m}}{32\mspace{14mu} {ft}^{2}}} = {{850\mspace{14mu} {lb}_{m}\mspace{20mu} \underset{\_}{{Step}\mspace{14mu} 5}\text{:}\mspace{14mu} {Calculate}\mspace{14mu} {the}\mspace{14mu} {mass}\mspace{14mu} {of}\mspace{14mu} {the}\mspace{14mu} {floor}\mspace{20mu} M_{floor}} = {{A_{floor}*\frac{1}{2}{{in}.\mspace{14mu} {thickness}}*A_{floor}\mspace{20mu} M_{floor}} = {{400\mspace{14mu} {ft}^{2}*\left\lbrack {\frac{1}{2}{in}*\frac{1\mspace{11mu} {ft}}{12\mspace{14mu} m}} \right\rbrack*\frac{45\mspace{14mu} {lb}_{m}}{{ft}^{2}}} = {750\mspace{14mu} {lb}_{m}\mspace{20mu} \underset{\_}{{Step}\mspace{14mu} 6}\text{:}\mspace{14mu} {Calculate}\mspace{14mu} {the}\mspace{14mu} {energy}\mspace{14mu} {released}\mspace{14mu} {by}\mspace{14mu} {walls}}}}}},{floor},{{and}\mspace{20mu} {{furnishings}\mspace{14mu} {between}\mspace{14mu} 70{^\circ}\mspace{14mu} {F.\left( {{init}.T} \right)}\mspace{14mu} {and}\mspace{14mu} 40{^\circ}\mspace{14mu} {F.\left( {{final}\mspace{14mu} T} \right)}}\mspace{20mu} {Heat}\mspace{14mu} {Transfer}\text{:}}} \right.}}}} & \; \\{{Q({Btu})} = {{\sum{\left( {M*c_{p}} \right)*\Delta \; T}} = {\Delta \left( {E_{floor} + E_{ceiling} + E_{walls} + E_{{furn}.}} \right)}}} & \; \\{\mspace{20mu} {{{\cdot \mspace{14mu} {Floor}}\text{:}\mspace{14mu} 750\mspace{14mu} {lb}_{m}*0.48\frac{B_{m}}{{lb}_{m}{^\circ}\mspace{14mu} {F.}}*\left( {70 - 40} \right)} = {{10800\mspace{14mu} {{Btu}\mspace{20mu} \circ \mspace{14mu} Q_{fl}}} = {10800\mspace{14mu} {Btu}}}}} & \; \\{\mspace{20mu} {{{\cdot \mspace{14mu} {Ceiling}}\text{:}\mspace{14mu} 850\mspace{14mu} {lb}_{m}*0.26\frac{B_{m}}{{lb}_{m}{^\circ}\mspace{14mu} {F.}}*\left( {70 - 40} \right)} = {{6630\mspace{14mu} {{Btu}\mspace{20mu} \circ \mspace{14mu} Q_{cl}}} = {6630\mspace{14mu} {Btu}}}}} & \; \\{\mspace{20mu} {{{\cdot \mspace{14mu} {Walls}}\text{:}\mspace{14mu} 1148\mspace{14mu} {lb}_{m}*0.26\; \frac{B_{m}}{{lb}_{m}{^\circ}\mspace{14mu} {F.}}*\left( {70 - 40} \right)} = {{8950\mspace{14mu} {{Btu}\mspace{20mu} \circ \mspace{14mu} Q_{wall}}} = {8950\mspace{14mu} {Btu}}}}} & \; \\{\mspace{20mu} {{{{{\cdot \mspace{14mu} {Furniture}}\text{:}\mspace{14mu} 200\mspace{14mu} {lb}_{m}*0.48\; \frac{B_{m}}{{lb}_{m}{^\circ}\mspace{14mu} {F.}}*\left( {70 - 40} \right)} = {{2880\mspace{14mu} {{Btu}\mspace{20mu} \circ \mspace{14mu} Q_{fur}}} = {2880\mspace{14mu} {Btu}}}}\mspace{20mu} {Q_{tot} = {{Q_{fl} + Q_{cl} + Q_{wall} + Q_{fur}} = {10800 + 6630 + 8950 + 2880}}}}\mspace{20mu} {Q_{tot} = {29260\mspace{14mu} {Btu}}}\mspace{20mu} {{{{Time}\mspace{14mu} {elasped}} - {11\text{:}00\mspace{14mu} {PM}\mspace{14mu} {to}\mspace{14mu} 6\text{:}00\mspace{14mu} {AM}}} = {7\mspace{14mu} {hours}}}\mspace{20mu} {{q\left( \frac{B_{m}}{hr} \right)} = {\frac{29260\mspace{14mu} {Btu}}{1\mspace{14mu} {hr}} = {4180\; \frac{Btu}{hr}}}}\mspace{20mu} {{Heat}\mspace{14mu} {to}\mspace{14mu} {Occupied}\mspace{14mu} {Room}}{{Estimate}\mspace{14mu} {the}\mspace{14mu} {energy}\mspace{14mu} {delivered}\mspace{14mu} {to}\mspace{14mu} {the}\mspace{14mu} {bedroom}\mspace{14mu} {if}\mspace{14mu} 29260\mspace{14mu} {Btu}\mspace{14mu} {are}\mspace{14mu} {extracted}\mspace{14mu} {from}\mspace{14mu} {the}\mspace{14mu} {room}\mspace{14mu} {{below}.\text{?}}\text{indicates text missing or illegible when filed}}}} & \;\end{matrix}$

Required Water Heat Storage Unit Size Calculation

-   Heat energy extracted from a room=Q=29260 [BTU]-   Constant pressure specific heat capacity of water=C_(p,w)=1.000    [BTU/lb_(m)F]-   Temperature delta=ΔT=50 [F]-   Mass of water=m_(w) [lb_(m)]

${Q\lbrack{BTU}\rbrack} = {{m_{w}\left\lbrack {lb}_{m} \right\rbrack}*{C_{p,w}\left\lbrack \frac{BTU}{{lb}_{m}F} \right\rbrack}*\Delta \; {T\lbrack F\rbrack}}$29260 = m_(w) * 1.000 * 50

-   m_(w)=585 lb_(m)-   Density of water=ρ_(w)=8.338 [lb_(m)/gal]-   Volume of water=V_(w) [gal]

ρ_(w)[lb_(m)/gal]=m _(w)[lb_(m) ]/V _(w)[gal]

8.338=585/V _(w)

-   V_(w)=70.2 gallons of water

Required Concrete Heat Storage Unit Size Calculation

-   Heat energy extracted from a room=Q=29260 [BTU]-   Constant pressure specific heat capacity of concrete=C_(p,c)=0.210    [BTU/lb_(m)F]-   Temperature delta=ΔT=50 [F]-   Mass of concrete=m_(c) [lb_(m)]

${Q\lbrack{BTU}\rbrack} = {{m_{c}\left\lbrack {lb}_{m} \right\rbrack}*{C_{p,c}\left\lbrack \frac{BTU}{{lb}_{m}F} \right\rbrack}*\Delta \; {T\lbrack F\rbrack}}$29260 = m_(c) * 0.210 * 50

-   M_(c)=2790 lb_(m)-   Density of concrete=ρ_(c)=150 [lb_(m)/ft³]-   Volume of concrete=V_(c) [ft³]

ρ_(c)[lb_(m)/ft³ ]=m _(c)[lb_(m) ]/V _(c)[ft³]

150=2790/V _(c)

-   V_(c)=19 ft³ of concrete

1. An apparatus for moving heat from a first room of a building to asecond room within said building for a first period of time and at asecond period of time moving heat from said second room to said firstroom, said apparatus comprising: A cooling air intake vent locatedinside of said first room, An evaporator fan for drawing cooling airfrom said cooling air intake vent across an evaporator and expellingsaid cooling air back into said first room, A compressor for circulatingcoolant through said evaporator to a condenser through coolant tubing, Acondenser fan drawing warming air from the second room across thecondenser and expelling said warming air back into the second room,wherein heat is transferred from said first room to said second roomduring the first period of time, and A value coupled to said coolanttubing that allows the coolant to reverse direction, thus transferringheat from said second room to said first room at the second period oftime.
 2. The apparatus of claim 1 wherein the first room is anunoccupied room during the first period of time.
 3. The apparatus ofclaim 1 wherein the second room is an occupied room during the firstperiod of time.
 4. The apparatus of claim 1 further comprising a secondevaporator in a third room connected via the coolant tubing, wherein thetubing incorporates values for directing said coolant to either theevaporator or the second evaporator.
 5. The apparatus of claim 1 furthercomprising a second condenser in a third room connected via the coolanttubing, wherein the tubing incorporates values for directing saidcoolant to either the condenser or the second condenser.
 6. The methodof claim 1 further comprising directing said coolant through valves to aheat exchanger at a thermal storage unit connected via the coolanttubing.
 7. A method for moving heat from a first room of a building to asecond room within said building for a first period of time and at asecond period of time moving heat from said second room to said firstroom, said method comprising: Drawing cooling air in from a cooling airintake vent located inside of said first room, Moving the cooling airwith an evaporator fan from the cooling air intake vent across anevaporator, Expelling the cooling air back into said first room,Circulating coolant with a compressor through coolant tubing from saidevaporator to a condenser, Drawing warming air with a condenser fan fromthe second room across the condenser, Expelling said warming air backinto the second room, Wherein heat is transferred from said first roomto said second room during the first period of time, and Transferringheat from said second room to said first room at the second period oftime, the transfer utilizing a value coupled to said coolant tubing thatallows the coolant to reverse direction.
 8. The method of claim 7wherein the first room is an unoccupied room during the first period oftime.